Single-component high-thermal-conductivity silicone mud and preparation method therefor

Abstract

The present invention relates to the field of heat-conducting interface materials, and in particular relates to single-component high-thermal-conductivity silicone mud and a preparation method therefor. The single-component high-thermal-conductivity silicone mud is composed of the following components: 100 parts of silicone oil, 10-50 parts of an MQ silicone resin, and 1500-2600 parts of a high-thermal-conductivity powder. The silicone mud further comprises 0.3-10 parts of a chain extender, 0.5-5 parts of a cross-linking agent, 1-10 parts of a catalyst, 5-20 parts of a tackifier, 5-15 parts of a plasticizer, and 1-5 parts of a pigment. In the present application, by cooperating both the silicone oil and the MQ silicone resin with a heat-conducting filler and other components, the heat-conducting silicone mud, which has good plasticity, high heat conductivity, low oil permeability and low high-and-low-temperature plastic deformability, can be obtained. Moreover, by further regulating and controlling the structures of the silicone oil and the MQ resin and the reaction conditions in the preparation process, the comprehensive performance of the silicone mud is further improved.

Description

A single-component high thermal conductivity silicon mud and its preparation method Technical Field

[0001] The present invention relates to the field of thermal conductive interface materials, and in particular to a single-component high thermal conductive silicon mud and a preparation method thereof. Background Art

[0002] With the rapid development of economic globalization and science and technology, people's living standards are constantly improving, and the demand for the quantity and quality of information communications is increasing. This requires devices with higher emissivity. To this end, the concept of 5G communication has been introduced. Compared with previous communication equipment, 5G technology requires equipment with higher operating power and more densely arranged components. This inevitably causes the equipment to generate more heat. If the heat cannot be transferred out in time, the accumulation of large amounts of heat will cause the local temperature of the components to be too high, causing the equipment to malfunction or even damage the equipment. In order to dissipate the heat in a timely manner, thermal conductive interface material is usually filled between the heat-generating device and the heat sink to ensure the normal operation of the electronic equipment.

[0003] Traditional thermal interface materials include thermal grease and thermal gaskets. Thermal grease is typically a mechanical mixture of low-viscosity inert silicone oil and thermal powder. It is widely used due to its simple and diverse construction methods. However, because the thermal powder and inert silicone oil in silicone grease easily separate and settle, especially at high temperatures, the inert silicone oil easily seeps out, causing the silicone grease to dry out and crack, increasing the thermal resistance at the interface, resulting in uneven heat dissipation and seriously affecting the service life of electronic devices. Thermal gaskets do not suffer from problems such as oil seepage and drying out like silicone grease. They are a fully cured elastomer structure that is easy to construct, clean, and has excellent resistance to high temperatures and impacts at high and low temperatures. However, they are not as well-adhered to the device as silicone grease, resulting in higher interface thermal resistance. In particular, under long-term high temperatures, the gasket tends to harden, forming gaps between the gasket and the interface, severely reducing thermal conductivity and affecting the heat transfer and stability of the device.

[0004] Patent publication number CN106398226A discloses a thermally conductive silicone gel and its preparation method, using vinyl-terminated polydimethylsiloxane and / or vinyl polymethylvinylsiloxane, with a base polymer of 100 parts; a crosslinker of 0.1-10 parts; a filler of 500-1800 parts; and a silane coupling agent of 0.1-15 parts. However, the use of low-molecular-weight vinyl-terminated polydimethylsiloxane and / or vinyl polymethylvinylsiloxane can lead to low-molecular-weight volatilization when used in high-temperature environments for a long time.

[0005] Patent publication number CN104497575A discloses a high-thermal-conductivity silicone paste. Its raw materials include silicone oil, thermally conductive powder filler, plasticizer, powder surface treatment agent, crosslinker, high-temperature resistant pigment, and platinum catalyst. The composition is based on weight: 100 parts silicone oil and 1000-1200 parts thermally conductive powder filler. The plasticizer is used in an amount of 0.5-1% by weight of the thermally conductive powder filler, and the powder surface treatment agent is used in an amount of 1-3% by weight of the powder filler. The crosslinker is used in an amount of 1-3% by weight of the silicone oil, the high-temperature resistant pigment is used in an amount of 5-10% by weight, and the platinum catalyst is used in an amount of 0.1-0.15% by weight. Low-viscosity silicone oil can emit low-molecular-weight volatiles during long-term use in high-temperature environments.

[0006] The patent with the authorization announcement number CN 110903656 B discloses a low-volatile heat-resistant thermal conductive silica gel mud material and its preparation method and application. The low-volatile heat-resistant thermal conductive silica gel mud material includes the following components in parts by mass: 100 to 1000 parts of thermal conductive filler, 100 parts of carrier, 2 to 5 parts of cross-linking agent, 3-5 parts of heat-resistant agent, and 1 to 2 parts of platinum catalyst. The present invention adopts methyl silicone rubber, methyl vinyl silicone rubber, and end-hydroxy silicone rubber, which not only have low volatility, but also have a larger molecular weight than the silicone oil system, have higher temperature resistance, and react with side chain hydrogen-containing polysiloxane under the catalysis of platinum catalyst to produce a silicone rubber with a low degree of cross-linking to achieve a plasticine-like shape, no flow, no solidification, no volatility, and high and low temperature resistance. However, the thermal conductive clay prepared by this patent has a large molecular weight of silicone rubber, which leads to reduced plasticity and wettability of the clay, which is not conducive to reducing the interfacial thermal resistance between the clay and the heat dissipation element.

[0007] To meet market demands for miniaturization, thinness, and lightweight electronic devices, dense packaging and high power consumption are the optimal solutions. However, this inevitably exacerbates the heat and aging of electronic devices. Therefore, ensuring efficient heat dissipation from these devices is crucial for ensuring the proper functioning of electronic devices and a major challenge in thermal management design. Consequently, there is an urgent need to develop a thermally conductive interface material that is easy to apply, offers low interfacial thermal resistance, excellent thermal conductivity, excellent thermal aging resistance, and resists drying and hardening. Summary of the Invention

[0008] This application aims to overcome the defects of thermal conductive materials in the prior art, such as easy oil seepage, high interface thermal resistance, and easy drying and hardening, and provides a single-component high thermal conductivity silicon mud and its preparation method to overcome the above shortcomings.

[0009] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions:

[0010] A single-component high thermal conductivity silicon mud, comprising the following components by weight: 100 parts silicone oil, 10 to 50 parts MQ silicone resin, and 1500 to 2600 parts high thermal conductivity powder;

[0011] It also includes 0.3 to 10 parts of chain extender, 0.5 to 5 parts of cross-linking agent, 1 to 10 parts of catalyst, 5 to 20 parts of tackifier, 5 to 15 parts of plasticizer, and 1 to 5 parts of pigment;

[0012] The silicone oil and MQ silicone resin both contain vinyl groups; and

[0013] The vinyl content of the MQ silicone resin is 2.5 to 15 times that of silicone oil;

[0014] The M / Q ratio of the MQ silicone resin is between 1.4 and 1.6.

[0015] Those skilled in the art should know that in order for the thermal conductive paste to achieve the best thermal conductivity, the most basic requirements for the thermal conductive paste are as follows: (1) good plasticity so that it can adapt to the needs of thermal conductive interfaces of various shapes; (2) no oil leakage or other phenomena will occur during use; (3) good thermal conductivity; (4) no plastic deformation will occur under high and low temperature conditions.

[0016] The thermal conductive adhesive in the prior art uses linear low molecular weight vinyl silicone oil or high molecular weight silicone rubber as the base material, then adds a certain amount of thermal conductive filler, crosslinking agent and catalyst to the base material oil, and crosslinks and cures at a certain temperature to obtain thermal conductive adhesive. However, the following problems are common in such thermal conductive adhesives: (1) When using low molecular weight vinyl silicone oil, in order to improve the plasticity of the thermal conductive adhesive, it is usually necessary to ensure that the overall crosslinking degree of the thermal conductive adhesive is at a low value, but this method will lead to more low molecular weight vinyl silicone oil causing oil leakage due to incomplete curing; (2) In order to overcome the oil leakage phenomenon, it is necessary to maintain a high crosslinking degree when using low molecular weight vinyl silicone oil as the base material, but too high a crosslinking degree will lead to a decrease in the plasticity of the thermal conductive adhesive; (3) When using high molecular weight silicone rubber as the base material, although its oil leakage is low under the condition of low crosslinking degree, due to the high viscosity of high molecular weight silicone rubber itself, its plasticity is still poor after curing.

[0017] In addition to adding conventional silicone oil, the single-component high thermal conductivity silicone mud in this application also adds a certain amount of MQ silicone resin. Compared with silicone oil, MQ silicone resin has lower viscosity and more reactive groups under the premise of the same molecular weight. Therefore, after compounding MQ silicone resin with silicone oil, it can have a higher cross-linking degree after cross-linking and curing with silicone oil, achieving the purpose of oil-proof, and at the same time, due to its higher plasticity. At the same time, due to the branched structure of MQ silicone resin itself, it can form a cross-linked interpenetrating network inside the silicone mud after reacting with linear silicone oil, so that the various components inside the mud can remain stable, further preventing the problem of separation and sedimentation of thermal conductive powder and silicone oil. At the same time, the formation of the cross-linked interpenetrating network can also effectively hinder the plastic deformation of silicone mud in hot and cold environments.

[0018] In addition, the applicant of this application unexpectedly discovered in routine experiments that the structural characteristics of silicone oil and MQ silicone resin itself have a significant impact on the comprehensive properties of the final silicone mud. These characteristics include the ratio of the vinyl content of MQ silicone resin to silicone oil and the M / Q ratio inside the MQ silicone resin.

[0019] Among them, for the ratio of the vinyl content of MQ silicone resin to silicone oil, the applicant found that the ratio between the two can determine the curing mode of the silicon mud in this application. When the ratio of the vinyl content of MQ silicone resin to silicone oil in this application is small or the vinyl content in silicone oil is higher than that of MQ silicone resin, silicone oil still plays a dominant role in the cross-linking process of silicon mud. At this time, MQ silicone resin cannot form a high-density cross-linked interpenetrating network structure inside the silicon mud. Therefore, under such conditions, after the silicon mud is prepared, oil seepage, thermal powder sedimentation, and plastic deformation of the silicon mud under hot and cold conditions will still occur. When the ratio of the vinyl content of MQ silicone resin to silicone oil is too high, MQ silicone resin will occupy an absolute position in the cross-linking process during the curing process of silicon mud, resulting in an excessively high cross-linking density inside the silicon mud, and a substantial decrease in the toughening and softening effect of linear silicone oil, thereby greatly reducing the plasticity of the prepared silicon mud. After actual testing, it was found that when the ratio of the vinyl content of MQ silicone resin to silicone oil is between 2.5 and 15, it can prevent the silicone oil or high thermal conductivity powder from leaking and separating and settling while ensuring that the silicone mud has good plasticity.

[0020] In addition to the vinyl content ratio of MQ silicone resin to silicone oil, the M / Q ratio within the MQ silicone resin itself also has a significant impact on the performance of silicone mud. M and Q in MQ silicone resin represent two different structural units. Among them, M represents a monofunctional silicon-oxygen chain (R3SiO), and its structural schematic is as follows: Q represents a tetrafunctional silicon-oxygen chain (SiO2), and its structural formula is as follows: . The applicant found that the greater the M / Q ratio inside the MQ silicone resin itself, the lower the degree of branching of the MQ silicone resin, and thus the fewer crosslinking points used to form a cross-linked interpenetrating network structure in the process of compounding the MQ silicone resin with silicone oil, resulting in oil seepage in the thermally conductive silicone mud and the problem of separation and sedimentation of high thermal conductivity powder. When the M / Q ratio inside the MQ silicone resin itself is smaller, the self-structure of the MQ resin is closer to the spherical crystal structure. At this time, the phase separation between it and other materials of the silicone mud is serious, so that the connection nodes between the silicone oil and the crosslinking agent only appear in a high density around the spherical crystal structure of the MQ silicone resin, and cannot be uniformly generated inside the silicone mud, resulting in the part of the silicone mud that does not contain MQ silicone resin still having the phenomenon of oil seepage. In addition, since the M / Q ratio inside the MQ silicone resin itself is too small, the presence of the crystal structure will also lead to an increase in the hardness of the MQ silicone resin, thereby causing the plasticity of the silicone mud to drop significantly.

[0021] Therefore, in summary, the present application can obtain high thermal conductivity silicon mud with good plasticity, no oil leakage and no separation and sedimentation by combining silicone oil and silicone resin. At the same time, by further controlling the structure of silicone oil and MQ resin, the comprehensive performance of silicon mud is further improved.

[0022] Preferably, the silicone oil is at least two of monovinyl-terminated hydroxy silicone oil, vinyl-terminated polydimethylsiloxane and polymethylphenyl-methylvinylsiloxane.

[0023] Preferably, the silicone oil has a viscosity of 100 mPa•s-1000 mPa•s and a vinyl mass fraction of 0.1%-0.4%.

[0024] Preferably, the MQ silicone resin is at least one of low-phenyl vinyl MQ silicone resin, epoxy-modified MQ silicone resin and vinyl MQ silicone resin.

[0025] The MQ silicone resin described in this application can be selected from unmodified vinyl MQ silicone resin, structurally controlled low-phenyl vinyl MQ silicone resin, or epoxy-modified MQ silicone resin. When low-phenyl vinyl MQ silicone resin is selected, the introduction of phenyl groups can effectively improve the long-term temperature resistance of the thermal conductive silicone mud.

[0026] Preferably, the vinyl mass fraction of the MQ silicone resin is between 1% and 1.5%.

[0027] Preferably, the molar fraction of phenyl groups in the low-phenyl vinyl MQ silicone resin is between 5% and 15%.

[0028] When using low-phenyl vinyl MQ silicone resin in this application, the mole fraction of phenyl groups within it has a certain impact on the performance of the silicone mud. When the phenyl mole fraction is too high, the plasticity of the silicone mud decreases, while when the phenyl mole fraction is too low, the long-term heat resistance of the thermal conductive silicone mud is not significantly improved. After testing, it was found that when the phenyl mole fraction is between 5% and 15%, a thermal conductive silicone mud with both good plasticity and good long-term heat resistance can be obtained.

[0029] Preferably, the epoxy modified MQ silicone resin has an epoxy value between 0.03 and 0.12.

[0030] Preferably, the high thermal conductivity powder comprises spherical thermal conductive particles accounting for 40%-60% of the total amount of the high thermal conductivity powder, nano-scale thermal conductive powder accounting for 20%-50% of the total amount of the high thermal conductivity powder, and flaky thermal conductive material accounting for 10%-30% of the total amount of the high thermal conductivity powder.

[0031] In the prior art, it is usually only necessary to add one thermally conductive filler to meet the actual thermal conductivity requirements. However, in this application, the applicant adopts a solution of compounding thermally conductive fillers with multiple different structures, so that the resulting high thermal conductivity powder has a higher thermal conductivity effect. The principle is that the spherical thermally conductive particles, nano-scale thermally conductive powder and flaky thermally conductive materials used in this application cooperate with each other, thereby effectively optimizing the thermal conductivity path of the product and making heat conduction smoother. At the same time, the addition of flaky thermally conductive materials can also form a flaky intercalated structure as shown in Figure 1, thereby effectively increasing the displacement resistance of other thermally conductive powders and reducing the plastic deformation of this thermally conductive silicon mud at high and low temperatures.

[0032] Preferably, the spherical thermally conductive particles are high-α-phase spherical alumina with an α-phase content greater than 97% and a particle size of 5-15 μm.

[0033] In this application, high α-phase spherical alumina with an α-phase content of >97% is selected as the thermal conductive filler. It has extremely high thermal conductivity. Therefore, under the premise that the silica mud has the same thermal conductivity coefficient, the amount of thermal conductive filler added can be effectively reduced, thereby greatly improving the plasticity of the thermal conductive silica mud.

[0034] Preferably, the nano-scale thermal conductive powder comprises at least one of high-α-phase nano-scale aluminum oxide and high-purity nano-scale zinc oxide with a particle size of 20-200 nm.

[0035] Preferably, the sheet-shaped thermally conductive material comprises a combination of at least one or more of boron nitride, aluminum hydroxide, and magnesium hydroxide with a particle size of 10-20 μm.

[0036] Preferably, the high thermal conductivity powder is surface-modified with octadecyltrimethoxysiloxane and vinyltriethoxysiloxane.

[0037] Preferably, the chain extender is a double-terminal low-hydrogen polysiloxane with a hydrogen mass fraction of 0.05% to 0.1%.

[0038] Preferably, the crosslinking agent is a blend of end-side hydrogenated silicone oil and hydrogenated silicone resin, wherein the viscosity of the end-side hydrogenated silicone oil is between 50 cps and 200 cps, and the mass fraction of hydrogen is between 0.05% and 0.15%, and the viscosity of the hydrogenated silicone resin is about 2500 to 3500 cps, and the mass fraction of hydrogen is between 0.1% and 0.2%.

[0039] Preferably, the tackifier is a blend of an epoxy silane coupling agent and a vinyl phenyl siloxane coupling agent, with a mass mixing ratio of 1:1 to 5:1.

[0040] Preferably, the plasticizer is at least one of methylphenyl silicone oil, methyl fluorine-containing silicone oil, and long-chain alkyl grafted dimethyl silicone oil.

[0041] In a second aspect, the present invention also provides a method for preparing the single-component high thermal conductivity silicon mud.

[0042] The preparation method comprises the following steps:

[0043] (1) Preparation of semi-finished products: Silicone oil, MQ silicone resin, and high thermal conductivity powder are weighed according to the proportion and added into a kneader, and vacuumed and mixed to obtain a semi-finished product for use;

[0044] (2) Preparation of finished products: weigh the semi-finished products, catalysts, cross-linking agents and other materials according to the proportion and put them into the kneader, keep the temperature and pressure and continue stirring to react, and stop stirring when the viscosity of the rubber material reaches the standard range;

[0045] (3) Repackaging: Wait until the temperature of the rubber material drops to room temperature before discharging and repackaging.

[0046] The thermally conductive silicone mud in this application is stirred and mixed in a kneader, cured and cross-linked at a certain temperature, and continuously plasticized into mud under high shear force, resulting in a material with similar plasticity and wettability to thermally conductive silicone grease, while also possessing its unique properties of permanent resistance to drying and cracking. Compared to solutions that require uniform mixing of the components before curing, the kneader-stirred pre-curing method described in this application enables the prepared silicone mud to have better resistance to oil seepage and thermal shock.

[0047] Therefore, the present invention has the following beneficial effects:

[0048] By combining silicone oil and MQ silicone resin with thermally conductive fillers and other components, this application produces a thermally conductive silicone sludge with good plasticity, high thermal conductivity, low oil permeability, and low high and low temperature plastic deformation. Furthermore, by further controlling the structure of the silicone oil and MQ resin, as well as the reaction conditions during the preparation process, the overall performance of the silicone sludge is further enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG1 is a simulation diagram of a sheet-like intercalation structure formed by sheet-like thermal conductive materials in a high thermal conductivity powder. Implementation Method

[0050] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below generally represent only a portion of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0051] [The influence of the vinyl content ratio of MQ silicone resin and vinyl silicone oil on the single-component high thermal conductivity silicone mud] Example

[0052] A single-component high thermal conductivity silicon mud, which is composed of the following components by weight:

[0053] (1) Silicone oil: 100 parts of vinyl-terminated polydimethylsiloxane with a viscosity of 500 mPa·s and a vinyl mass fraction of 0.2%;

[0054] (2) MQ silicone resin: 30 parts of vinyl MQ silicone resin with a vinyl mass fraction of 0.5% and an M / Q ratio of 1.5;

[0055] (3) High thermal conductivity powder: 2000 parts of high α-phase spherical alumina with α-phase content > 97% and particle size of 5-15 μm;

[0056] (4) Chain extender: 0.3 to 10 parts of double-terminal low-hydrogen polysiloxane with a hydrogen mass fraction of 0.08%;

[0057] (5) Cross-linking agent: 1 part of end-side hydrogenated silicone oil with a viscosity of 150 cps and a hydrogen mass fraction of 0.1%;

[0058] (6) Cross-linking agent: 3 parts of hydrogenated silicone resin with a viscosity of 30500 cps and a hydrogen content of 0.15%;

[0059] (7) Tackifier: 10 parts of a mixture of γ-glycidyloxypropyldiethoxysilane and vinyltriethoxysilane in a mass ratio of 2:1;

[0060] (8) Plasticizer: 10 parts of methylphenyl silicone oil;

[0061] (9) 3 parts of pigment;

[0062] (10) Catalyst: platinum catalyst, platinum content is 3000ppm 5 parts.

[0063] The preparation method of single-component high thermal conductivity silicon mud is as follows:

[0064] 01) Preparation of semi-finished product: Weigh silicone oil, MQ silicone resin and high thermal conductivity powder according to the proportion and add them into the kneader. Mix them evenly under vacuum at 150℃ to obtain the semi-finished product for use;

[0065] 02) Finished product preparation: weigh the semi-finished product, catalyst, cross-linking agent and other materials according to the proportion and put them into the kneader. Keep the temperature and pressure (60℃ / -0.095Mpa) and continue stirring for 2 hours. Stop stirring when the viscosity of the rubber reaches the standard range.

[0066] 03) Repackaging: Wait until the temperature of the rubber material drops to room temperature before discharging and repackaging.

[0067] Example 2

[0068] Example 2 had essentially the same ingredients as Example 1, except that the vinyl content of the MQ silicone resin was adjusted to 1%. (The vinyl content of MQ silicone resin is five times that of vinyl-terminated polydimethylsiloxane.)

[0069] Example 3

[0070] Example 3 has essentially the same ingredients as Example 1, except that the vinyl-terminated polydimethylsiloxane is replaced with a vinyl-terminated polydimethylsiloxane with a viscosity of 100 mPa·s and a vinyl content of 0.4%. Accordingly, the vinyl content of the MQ silicone resin is adjusted to 1.2%. (The vinyl content of the MQ silicone resin is three times that of the vinyl-terminated polydimethylsiloxane.)

[0071] Example 4

[0072] Example 4 has essentially the same ingredients as Example 1, except that the vinyl-terminated polydimethylsiloxane is replaced with a vinyl-terminated polydimethylsiloxane with a viscosity of 1000 mPa·s and a vinyl content of 0.1%. Accordingly, the vinyl content of the MQ silicone resin is adjusted to 1.5%. (The vinyl content of the MQ silicone resin is 15 times that of the vinyl-terminated polydimethylsiloxane.)

[0073] Comparative Example 1

[0074] Comparative Example 1 had essentially the same ingredients as Example 1, except that the vinyl content of the MQ silicone resin was adjusted to 0.2%. (The vinyl content of the MQ silicone resin is twice that of the vinyl-terminated polydimethylsiloxane.)

[0075] Comparative Example 2

[0076] Comparative Example 1 had essentially the same ingredients as Example 1, except that the vinyl content of the MQ silicone resin was adjusted to 4%. (The vinyl content of the MQ silicone resin is 20 times that of the vinyl-terminated polydimethylsiloxane.)

[0077] According to the above embodiment formula, a variety of thermal conductive silicon muds were prepared and their basic properties and high temperature resistance, oil permeation resistance, and thermal shock resistance were tested. The results are shown in Table 1.

[0078] Table 1

[0079]

[0080] [The influence of MQ silicone resin M / Q ratio on single-component high thermal conductivity silicone mud] Example

[0081] The components of Example 5 are substantially the same as those of Example 1, except that the M / Q ratio of the MQ silicone resin is adjusted to 1.4.

[0082] Example 6

[0083] The components of Example 6 are substantially the same as those of Example 1, except that the M / Q ratio of the MQ silicone resin is adjusted to 1.6.

[0084] Comparative Example 3

[0085] The components of Comparative Example 3 are substantially the same as those of Example 1, except that the M / Q ratio of the MQ silicone resin is adjusted to 1.0.

[0086] Comparative Example 4

[0087] The components of Comparative Example 4 are substantially the same as those of Example 1, except that the M / Q ratio of the MQ silicone resin is adjusted to 2.0.

[0088] According to the above embodiment formula, a variety of thermal conductive silicon muds were prepared and their basic properties and high temperature resistance, oil resistance, and resistance to cold and hot shock were tested. The results are shown in Table 2.

[0089] Table 2

[0090]

[0091] [The influence of MQ silicone resin structure on single-component high thermal conductivity silicone mud] Example

[0092] The components of Example 7 are substantially the same as those of Example 1, except that the vinyl MQ silicone resin is replaced with a low-phenyl vinyl MQ silicone resin having a phenyl molar fraction of 5%.

[0093] Example 8

[0094] The components of Example 8 are substantially the same as those of Example 1, except that the vinyl MQ silicone resin is replaced with a low-phenyl vinyl MQ silicone resin having a phenyl molar fraction of 10%.

[0095] Example 9

[0096] The components of Example 9 are substantially the same as those of Example 1, except that the vinyl MQ silicone resin is replaced with a low-phenyl vinyl MQ silicone resin having a phenyl molar fraction of 15%.

[0097] Example 10

[0098] The components of Example 10 are substantially the same as those of Example 1, except that the vinyl MQ silicone resin is replaced with an epoxy-modified vinyl MQ silicone resin having an epoxy value of 0.03.

[0099] Example 11

[0100] The components of Example 11 are substantially the same as those of Example 1, except that the vinyl MQ silicone resin is replaced with an epoxy-modified vinyl MQ silicone resin having an epoxy value of 0.08.

[0101] Example 12

[0102] The components of Example 12 are substantially the same as those of Example 1, except that the vinyl MQ silicone resin is replaced with an epoxy-modified vinyl MQ silicone resin having an epoxy value of 0.12.

[0103] Comparative Example 5

[0104] The components of Comparative Example 5 are substantially the same as those of Example 1, except that the vinyl MQ silicone resin is replaced with a phenyl vinyl MQ silicone resin having a phenyl mole fraction of 20%.

[0105] Comparative Example 6

[0106] The components of Comparative Example 6 are substantially the same as those of Example 1, except that the vinyl MQ silicone resin is replaced with an epoxy-modified vinyl MQ silicone resin having an epoxy value of 0.2.

[0107] According to the above embodiment formula, a variety of thermal conductive silicon muds were prepared and their basic properties and high temperature resistance, oil resistance, and resistance to cold and hot shock were tested. The results are shown in Table 3.

[0108] Table 3

[0109]

[0110] [The influence of high thermal conductivity powder composition on single-component high thermal conductivity silicon mud] Example

[0111] The components of Example 13 are basically the same as those of Example 1, except that the high thermal conductivity powder is replaced.

[0112] In this embodiment, the high thermal conductivity powder includes:

[0113] 1000 parts of high α-phase spherical alumina with α-phase content > 97% and particle size of 5-15 μm;

[0114] 400 parts of high α-phase nano-alumina with a particle size of 20-200 nm;

[0115] 600 parts of boron nitride with a particle size of 10-20 μm.

[0116] Example 14

[0117] The components of Example 14 are basically the same as those of Example 1, except that the high thermal conductivity powder is replaced.

[0118] In this embodiment, the high thermal conductivity powder includes:

[0119] 800 parts of high α-phase spherical alumina with an α-phase content of >97% and a particle size of 5-15 μm;

[0120] 1000 parts of high α-phase nano-alumina with a particle size of 20-200 nm;

[0121] 200 parts of boron nitride with a particle size of 10-20 μm.

[0122] Example 15

[0123] The components of Example 15 are basically the same as those of Example 1, except that the high thermal conductivity powder is replaced.

[0124] In this embodiment, the high thermal conductivity powder includes:

[0125] 1200 parts of high α-phase spherical alumina with an α-phase content of >97% and a particle size of 5-15 μm;

[0126] 400 parts of high α-phase nano-alumina with a particle size of 20-200 nm;

[0127] 400 parts of boron nitride with a particle size of 10-20 μm.

[0128] According to the above embodiment formula, a variety of thermal conductive silicon muds were prepared and their basic properties and high temperature resistance, oil resistance, and resistance to cold and hot shock were tested. The results are shown in Table 4.

[0129] Table 4

[0130]

[0131] [The influence of high thermal conductivity powder composition on single-component high thermal conductivity silicon mud] Example

[0132] A single-component high thermal conductivity silicon mud, which is composed of the following components by weight:

[0133] (1) Silicone oil: 100 parts of vinyl-terminated polydimethylsiloxane with a viscosity of 500 mPa·s and a vinyl mass fraction of 0.2%;

[0134] (2) MQ silicone resin: 10 parts of vinyl MQ silicone resin with a vinyl mass fraction of 1.5% and an M / Q ratio of 1.5;

[0135] (3) High thermal conductivity powder: 750 parts of high α-phase spherical alumina with α-phase content > 97% and particle size of 5-15 μm;

[0136] High thermal conductivity powder: 300 parts of high α-phase nano-alumina with a particle size of 20-200 nm;

[0137] High thermal conductivity powder: 450 parts of 10-20 μm boron nitride;

[0138] (4) Chain extender: 10 parts of double-terminated low-hydrogen polysiloxane with a hydrogen mass fraction of 0.05%;

[0139] (5) Cross-linking agent: 0.5 parts of end-side hydrogenated silicone oil with a viscosity of 50 cps and a hydrogen mass fraction of 0.15%;

[0140] (6) Cross-linking agent: 4.5 parts of hydrogenated silicone resin with a viscosity of 3500 cps and a hydrogen content of 0.1%;

[0141] (7) Tackifier: 5 parts of a mixture of γ-glycidyloxypropyldiethoxysilane and vinyltriethoxysilane in a mass ratio of 1:1;

[0142] (8) Plasticizer: 5 parts of methylphenyl silicone oil;

[0143] (9) 1 part of pigment;

[0144] (10) Catalyst: platinum catalyst, platinum content is 3000ppm 1 part.

[0145] Example 17

[0146] A single-component high thermal conductivity silicon mud, which is composed of the following components by weight:

[0147] (1) Silicone oil: 100 parts of vinyl-terminated polydimethylsiloxane with a viscosity of 500 mPa·s and a vinyl mass fraction of 0.2%;

[0148] (2) MQ silicone resin: 50 parts of vinyl MQ silicone resin with a vinyl mass fraction of 1% and an M / Q ratio of 1.6;

[0149] (3) High thermal conductivity powder: 1300 parts of high α-phase spherical alumina with α-phase content > 97% and particle size of 5-15 μm;

[0150] High thermal conductivity powder: 650 parts of high α-phase nano-alumina with a particle size of 20-200 nm;

[0151] High thermal conductivity powder: 650 parts of 10-20 μm boron nitride;

[0152] (4) Chain extender: 0.3 parts of double-terminated low-hydrogen polysiloxane with a hydrogen mass fraction of 0.1%;

[0153] (5) Cross-linking agent: 1 part of end-side hydrogenated silicone oil with a viscosity of 200 cps and a hydrogen mass fraction of 0.05%;

[0154] (6) Cross-linking agent: 3 parts of hydrogenated silicone resin with a viscosity of 2500 cps and a hydrogen content of 0.2%;

[0155] (7) Tackifier: 20 parts of a mixture of γ-glycidyloxypropyldiethoxysilane and vinyltriethoxysilane in a mass ratio of 5:1;

[0156] (8) Plasticizer: 15 parts of methylphenyl silicone oil;

[0157] (9) 5 parts of pigment;

[0158] (10) Catalyst: platinum catalyst, platinum content is 3000ppm 10 parts.

[0159] According to the above embodiment formula, a variety of thermal conductive silicon muds were prepared and their basic properties and high temperature resistance, oil permeation resistance, and thermal shock resistance were tested. The results are shown in Table 5.

[0160] Table 5

[0161]

[0162] Comparative Example 7

[0163] The ingredients of Comparative Example 7 are exactly the same as those of Example 1, except that the preparation method is changed.

[0164] The preparation method of single-component high thermal conductivity silicon mud is as follows:

[0165] 01) Preparation of semi-finished product: Add all materials into the kneader and mix them evenly at room temperature to obtain the semi-finished product;

[0166] 02) Finished product preparation: The semi-finished product was cured at 150°C under vacuum (-0.095 MPa) for 2 hours;

[0167] 03) Repackaging: Wait until the temperature of the rubber material drops to room temperature before discharging and repackaging.

[0168] According to the above comparative example method, thermal conductive silicon mud was prepared and its basic properties and high temperature resistance, oil resistance, and resistance to cold and hot shock were tested. The results are shown in Table 6.

[0169] Table 6

[0170]

[0171] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A single-component high thermal conductivity silicon mud, characterized in that: The single-component high thermal conductivity silicon mud is composed of the following components by weight: 100 parts of silicone oil, 10 to 50 parts of MQ silicone resin, and 1500 to 2600 parts of high thermal conductivity powder; It also includes 0.3 to 10 parts of chain extender, 0.5 to 5 parts of cross-linking agent, 1 to 10 parts of catalyst, 5 to 20 parts of tackifier, 5 to 15 parts of plasticizer, and 1 to 5 parts of pigment; The silicone oil and the MQ silicone resin both contain vinyl; and, The vinyl content of the MQ silicone resin is 2.5 to 15 times that of silicone oil; The M / Q ratio of the MQ silicone resin is between 1.4 and 1.

6.

2. The one-component high thermal conductivity silicon mud according to claim 1, characterized in that: The silicone oil is at least two of monovinyl-terminated hydroxy silicone oil, vinyl-terminated polydimethylsiloxane and polymethylphenyl-methylvinylsiloxane.

3. The one-component high thermal conductivity silicon mud according to claim 2, characterized in that: The viscosity of the vinyl silicone oil is 100 mPa·s-1000 mPa·s, and the mass fraction of vinyl is 0.1%-0.4%.

4. The one-component high thermal conductivity silicon mud according to claim 1, characterized in that: The MQ silicone resin is at least one of low-phenyl vinyl MQ silicone resin, epoxy-modified vinyl MQ silicone resin and vinyl MQ silicone resin; The vinyl mass fraction of the MQ silicone resin is between 1% and 1.5%.

5. The one-component high thermal conductivity silicon mud according to claim 4, characterized in that: The phenyl mole fraction of the low phenyl vinyl MQ silicone resin is below 5-15%; The epoxy modified vinyl MQ silicone resin has an epoxy value between 0.03 and 0.

12.

6. The one-component high thermal conductivity silicon mud according to claim 1, characterized in that: The high thermal conductivity powder comprises spherical thermal conductive particles accounting for 40%-60% of the total amount of the high thermal conductivity powder, nano-scale thermal conductive powder accounting for 20%-50% of the total amount of the high thermal conductivity powder, and flaky thermal conductive materials accounting for 10%-30% of the total amount of the high thermal conductivity powder.

7. The one-component high thermal conductivity silicon mud according to claim 6, characterized in that: The spherical thermally conductive particles are high-α-phase spherical alumina with an α-phase content of more than 97% and a particle size of 5-15 μm; The nano-scale thermal conductive powder material comprises at least one of high α-phase nano-scale aluminum oxide and high-purity nano-scale zinc oxide with a particle size of 20-200 nm; The sheet-shaped heat-conducting material includes at least one or more of boron nitride, aluminum hydroxide, and magnesium hydroxide with a particle size of 10-20 μm.

8. A single-component high thermal conductivity silicon mud according to claim 1, 6 or 7, characterized in that: The high thermal conductivity powder is surface-modified by octadecyl trimethoxysiloxane and vinyl triethoxysiloxane.

9. The one-component high thermal conductivity silicon mud according to claim 1, characterized in that: The chain extender is a double-terminal low-hydrogen polysiloxane with a hydrogen content of 0.05% to 0.1%; The crosslinking agent is a blend of end-side hydrogenated silicone oil and hydrogenated silicone resin, wherein the end-side hydrogenated silicone oil has a viscosity between 50 cps and 200 cps, a hydrogen content between 0.05% and 0.15%, and the hydrogenated silicone resin has a viscosity between 2500 and 3500 cps, and a hydrogen content between 0.1% and 0.2%; The tackifier is a blend of an epoxy silane coupling agent and a vinyl phenyl siloxane coupling agent, and the mass mixing ratio is between 1:1 and 5:1; The plasticizer is at least one of methylphenyl silicone oil, methyl fluorine-containing silicone oil, and long-chain alkyl grafted dimethyl silicone oil.

10. A method for preparing a single-component high thermal conductivity silicon mud as claimed in any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: (1) Preparation of semi-finished products: Weigh silicone oil, silicone resin and filler according to the proportion and add them into a kneader, vacuum and mix them evenly for use; (2) Finished product preparation: Weigh the semi-finished product, catalyst, cross-linking agent and other materials according to the proportion and put them into the kneader. Keep the temperature and pressure and continue stirring to react. Stop stirring when the viscosity of the rubber material reaches the standard range. (3) Packaging: Wait until the temperature of the rubber material drops to room temperature before discharging and packaging.

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